This invention relates to apparatus and methods for continuous or batch type low temperature cleansing of foodware items in commercial dishwashers.
Hot water sanitizing type dishwashers rely on the use of high temperature (180.degree. F. and above) water in order to sanitize the foodware items in the final rinse stage. If, however, a limited capacity of hot water is available and the temperature thereof falls below the required level for destruction of bacterial and microbial life, other precautions must be taken to sanitize the foodware items in the final rinse.
In this instance, some commercial dishwashers use a so called "booster heater" which either has an electrical heating element or a gas burner heater in the dishwashing machine to heat the rinse water to a higher level. However this added equipment is inherently expensive in the manufacture of the dishwashing machine and is also expensive to operate.
Other commercial dishwashing machines, see for example U.S. Pat. No. 4,277,290 issued to Andrews et al. for Low Temperature Washing and Chemical Sanitizing of Foodware, automatically and regularly inject a liquid chemical sanitizing agent into the flow of water in the rinse line. Typical sanitizers are the hypochlorides, chloramines and other organic chlorine-liberating compounds, quaternary ammonium compounds, and certain iodophors. The chlorine -liberating compounds are generally preferred.
A general problem with the commercial dishwashing machines of the prior art, when utilized for low temperature washing and chemical sanitizing of foodware, is that they automatically inject a sanitizer to the rinse water, either before or after the discharge of the rinse water into the dishwasher chamber, whether or not the rinse water temperature is in and of itself adequately high to sanitize the foodware items, thereby wasting sanitizer even when the rinse water temperature is sufficiently high.
It is a principal object of the present invention to eliminate this shortcoming and to further provide a commercial dishwasher which also eliminates the need or requirement of utilizing any type of booster heater for heating the final rinse water for the purposes of sanitizing.